At its inception radio telephony was designed, and used for, voice communications. As the consumer electronics industry continued to mature, and the capabilities of processors increased, more devices became available that allowed the wireless transfer of data between devices and more applications became available that operated based on such transferred data. Of particular note are the Internet and local area networks (LANs). These two innovations allowed multiple users and multiple devices to communicate and exchange data between different devices and device types. With the advent of these devices and capabilities, users (both business and residential) found the need to transmit data, as well as voice, from mobile locations.
The infrastructure and networks which support this voice and data transfer have likewise evolved. Limited data applications, such as text messaging, were introduced into the so-called “2G” systems, such as the Global System for Mobile (GSM) communications. Packet data over radio communication systems became more usable in GSM with the addition of the General Packet Radio Services (GPRS). 3G systems and, then, even higher bandwidth radio communications introduced by Universal Terrestrial Radio Access (UTRA) standards made applications like surfing the web more easily accessible to millions of users (and with more tolerable delay).
Even as new network designs are rolled out by network manufacturers, future systems which provide greater data throughputs to end user devices are under discussion and development. For example, the 3GPP Long Term Evolution (LTE) standardization project is intended to provide a technical basis for radiocommunications in the decades to come. Among other things of note with regard to LTE systems is that they will provide for downlink communications (i.e., the transmission direction from the network to the mobile terminal) using orthogonal frequency division multiplexing (OFDM) as a transmission format and will provide for uplink communications (i.e., the transmission direction from the mobile terminal to the network) using single carrier frequency division multiple access (FDMA).
Regardless of the standardized system being implemented, communication system base stations in such systems operate as access points for mobile users and typically handle bands and channels that are commissioned during an installation or upgrade activity. The bands and channels which are used by a particular base station typically remain fixed after the base station has been commissioned and are used by that base station for long periods of time, e.g., years, to support radiocommunication services with mobile subscribers. The number of channels and/or the bandwidths of the channels with which the base station is commissioned for operation are typically chosen from a small number of options, e.g., based on a particular air interface standard.
However, the number of frequency bands, as well as the number of licensed sub-band bandwidths, available for communication networks continue to increase over time. In addition it may be possible to opportunistically use portions of the spectrum at times when it is otherwise underused. Moreover there are dynamic situations where the demand for communication can change rapidly in a geographic as well as a temporal sense. Since, as mentioned above, existing systems typically handle only a small number of channels and/or bandwidths and have bandwidths that are not rapidly changeable, there are many situations where the utilization of spectrum is not as efficient as it could be.